Along with inhibition of the PDE4 enzyme, apremilast deregulates production of substantial chemokines and cytokines, including CXCL9, CXCL10, TNF-α, IFN-α, IL-2, IL-12, and IL-23, in the human primary peripheral blood mononuclear cells as well as TNF-α in the natural killer cells and epidermal keratinocytes, as suggested in a preclinical model of psoriasis. Here, TNF is linked to psoriasis.